1. Field of the Invention
This invention relates to a webbing retractor of a seatbelt device in a vehicle for reducing a winding urging force of the restraining webbing on an occupant.
2. Description of the Related Art
In a seatbelt device for a vehicle, a webbing retractor for decreasing a winding force is used, the retractor of which has a pair of resilient members provided in series for applying a webbing retracting urging force to a winding shaft. A connecting portion between the resilient members can be locked so that the urging force of one of the resilient members is not transmitted to an occupant while the seatbelt device is being worn.
As disclosed in the Japanese Utility Model Application Laid Open No. 60-44856, as an example, a retractor device is constructed such that each end of a pair of resilient members connected in series is engaged with a ratchet wheel, and when a webbing is applied to an occupant, a pawl is engaged with the ratchet wheel so that a winding urging force of one of the resilient members is not transmitted to a winding shaft.
In this type of webbing retractor, when the winding shaft is rotated in a webbing winding direction after the occupant releases the webbing, the rotating force is transmitted to a cam plate and the cam plate forcedly releases a pawl from the ratchet wheel, the winding force of both resilient members is transmitted to the winding shaft and a positive winding force is generated. Due to this arrangement, when the rotation of a connecting wheel in a webbing winding direction is transmitted to the cam plate, the full winding force is released by a slight winding operation even though the occupant is still in the seatbelt device. However, since a more certain amount of pulling-out or winding operation is performed, by the wearer it is desirable that the full winding force is not released.
The conventional type of cam plate is constructed such that projections fit into a ring-shaped groove of the connecting wheel which rotates together with the winding shaft when the webbing is to be wound, the cam plate may start to rotate after its maximum one rotation in reference to its relative position with respect to the connection wheel and in addition when the connection wheel is rotated in its maximum one rotation, the cam plate may forcedly move the pawl away from the ratchet wheel.